1999 Saturn SL2 starting issues

[onlyk]

I have an intermittent starting problem on my 99 Saturn SL2. I have a basic knowledge of cars, and after replacing the battery which was recommended to me, I can verify the following: starter and battery are performing great, I have cleaned the ground connectors between the transmission and battery. when the car is in the no start mode with all the spark plugs out and laying on the intake manifold, all plugs have good spark. at the same time, i have good fuel pressure at the fuel bar (50 lb.). when i put the spark plugs back in and try to start the car again, i spray starting fluid into the intake manifold and the car still does not start, which baffles me. after doing this, i take a spark plug out, and they appear to be dry. when the car DOES start at certain times, it starts very rough and idles rough, like its not running on all cylinders for 20 seconds or so, then clears up into a very fine idle. i have no codes, but previously, i did have an EGR code which has since been replaced. when the engine is off, and i turn the key so all the lights on the dashboard come on (and the service engine light comes on, but does not click off after 5-10 seconds as i am used to seeing on other vehicles), is this normal? the car is a 5 speed, and i have read on other forums talking about a bad coolant sensor, ignition module, or even an ECU issue, but rather than buying all these parts for it and taking a shot in the dark, i would greatly appreciate any advice or guidance, thanks.